Reply to thread

Message

<blockquote data-quote="Peter Kowalczyk" data-source="post: 9384" data-attributes="member: 4308">I&#039;m looking for a source for absorptive acoustic foam in small bulk qtys (~50- 200 sq ft).&nbsp; IIRC, this has been discussed before, but my search of the forums results in lots of posts about grille foam, but few about acoustic absorption.&nbsp; Must be flame-retartdant.&nbsp; This source looks appropriate:&nbsp; <a href="http://www.foambymail.com/acoustical-foam-products.html" target="_blank">Acoustical Foam - Soundproofing, Sound Insulation &amp; Control Foam</a>, but I&#039;m wondering what others may be available.And some questions to guide my search:1) Is it a safe rule of thumb to say that the total RT60 reduction at any given frequency is correlated to the % coverage, while the absorption at low frequencies is correlated with foam thickness?&nbsp; Or conversely, could one trade off thickness for coverage (thicker foam, less coverage) and get similar results?&nbsp; 2) I see some materials specified with an absorption coefficient GREATER than 1 at certain (higher) frequencies, which seems impossible - how can a material absorb more than 100% of incident acoustic energy?&nbsp; What does this imply?</blockquote>

[QUOTE="Peter Kowalczyk, post: 9384, member: 4308"] I'm looking for a source for absorptive acoustic foam in small bulk qtys (~50- 200 sq ft). IIRC, this has been discussed before, but my search of the forums results in lots of posts about grille foam, but few about acoustic absorption. Must be flame-retartdant. This source looks appropriate: [URL="http://www.foambymail.com/acoustical-foam-products.html"]Acoustical Foam - Soundproofing, Sound Insulation & Control Foam[/URL], but I'm wondering what others may be available. And some questions to guide my search: 1) Is it a safe rule of thumb to say that the total RT60 reduction at any given frequency is correlated to the % coverage, while the absorption at low frequencies is correlated with foam thickness? Or conversely, could one trade off thickness for coverage (thicker foam, less coverage) and get similar results? 2) I see some materials specified with an absorption coefficient GREATER than 1 at certain (higher) frequencies, which seems impossible - how can a material absorb more than 100% of incident acoustic energy? What does this imply? [/QUOTE]

Verification